More AT40 Info:

With the February 8, 2003 show, the AC version of
American Top 20 changed charts. Instead of using Radio &
Records' AC chart, AT20 AC now used an unpublished Mediabase AC chart.
The new chart was different than the R&R chart in the following
ways: 1) Songs played on the syndicated daily "Delilah" show were not
counted toward the chart, and 2) The chart was ranked based on audience
impressions rather than just how many times a song is played.
No information was available for the recurrent rules of the new chart.
This information came from a staff member of AT20 and is listed here
with permission.

Recurrent
rule change of late 2001

With the November 2nd 2001 issue, Radio
& Records changed its recurrent rule again. For the
CHR/Pop chart, which AT40 followed at the time, the recurrent rule reverted
back to 20 weeks on and below #20. This was the same rule that
R&R used before its charts changed back in August.

For the AT20 shows, the recurrent rule changed to 20
weeks on and below #15. This was a new rule for these charts.

For a history of the chart saga and some differences
between R&R & AT40 during the separation, see below.

AT40 chart change from 10/21/2000 through
8/10/2001

Casey Kasem and his staff used R&R for the
source of their charts from January 1989 to October 14, 2000. On
October 21, 2000, AT40 switched from R&R to a chart provided by
Mediabase 24/7. The Mediabase 24/7 chart appeared to have no coherent
recurrent rule, and songs were removed from the chart from as high as
#10. AT40 said that their new chart was better than R&R's, and
that the new chart would provide a "fresher" sound since the chart
supposedly moved faster. R&R staff have said that AT40 actually
changed charts because Mediabase charts were available to AT40 a few
days earlier, giving AT40 writers more time to prepare the show.

On August 10, 2001, R&R changed its charts to
Mediabase only data as well as its recurrent rule. With the chart
change, the chart was now available a few days earlier, and thus AT40
decided to go back to the chart. The 1st AT40 show that used AT40's new
chart was August 18, 2001.

Here is a summary of some of the differences between
R&R and AT40 during the separation:

63% of all songs that debuted during the separation
debuted first on AT40, then on R&R at least 1 week later.

The longest wait between a song debuting on AT40 and
then R&R was 5 weeks, by American Hi-Fi's "Flavor of the Weak".

58% of all songs that fell off AT40 during the
separation fell off earlier on AT40 than on R&R.

In terms of #1 songs: "Again" by Lenny Kravitz reached
#1 on R&R but not on AT40, and "Survivor" by Destiny's Child
reached #1 on AT40 but not R&R.

Many thanks to GordonUM from the former
R&R Messagebords for compiling the above chart information.

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interest in the radio show "American Top 40". This site has no
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and Records Magazine. The official AT40 site is at40.com All copyrights and trademarks remain property of
their respective owners.
Original artwork at the very top of this page is copyright 2001 by
Meowycats.
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